But that was not the case, say authorities. Billingslea is accused of breaking into an Arlington woman’s home on Sunday evening, beating and raping her at knifepoint.

On Monday, Billingslea, 45, was ordered held without bail until a June 6 dangerousness hearing. He pleaded not guilty to charges of aggravated rape, kidnapping, home invasion, and assault and battery.

Sexual assault specialists said the alleged crime shows the inherent risks in releasing chronic sex offenders like Billingslea — who was classified as a Level 3 offender, the most likely to reoffend — even after many years in custody.

“Clearly, he was dangerous,” said Gina Scaramella, executive director of the Boston Area Rape Crisis Center. “The assessment that he wasn’t was obviously incorrect.”

At the time of the jury’s March 2013 vote to free Billingslea, there were words of warning. A five-member board of psychologists appointed by the state said he showed characteristics of antisocial personality disorder and would be likely to offend again.

He lacked “regard for others” and “power to control his sexual impulses,” the board wrote in its report. “He has also displayed a pattern of deceit and a reckless disregard for the rights of others.”

But jurors, members of a special panel convened to determine whether it was safe to release Billingslea, voted 12 to 2 in favor of freeing him.

Joan Tabachnick, executive director of the Massachusetts Adolescent Sex Offender Coalition, said Monday that treatment is critical to reducing the risks of recidivism. A 2004 court document stated that Billingslea had briefly participated in sex offender therapy in prison before being terminated for poor attendance.

“Prison time alone won’t teach anyone how to not rape again,” she said. “This is a really horrific act by someone who clearly wasn’t ready to be in the community, in hindsight.”

Police said the Arlington woman sustained serious injuries. Officers went to the woman’s home after she called a friend, who notified police.

When they arrived, Billingslea ran out the back door, police said. Officers caught him after a short chase.

Arlington Police Chief Frederick Ryan
said Billingslea may have been staying with a relative. Investigators are looking into the possibility that the woman was targeted, Ryan said.

Authorities did not release any more details on the woman who was attacked. Billingslea’s court-appointed lawyer declined to comment Monday.

Billingslea had listed a Boston homeless shelter as his address for the state’s sex offender registry.

At the request of prosecutors, the case was sealed. But previous court records show Billingslea’s history of sexual crimes dating to 1986, when he placed a switchblade to the throat of a 14-year-old in Boston and demanded sex. When she refused, he held her arms while a second boy removed her clothes.

In the assault on the 13-year-old, Billingslea was convicted in 1989 and sentenced to five years in prison. Once he was out, in December 1993, he raped an 11-year-old, a friend of his girlfriend’s daughter.

He was convicted and was sentenced to a maximum of 10 years in prison. But before his release, the Suffolk district attorney’s office sought to have him designated as a sexually dangerous person, allowing the state to hold him indefinitely at a treatment center in Bridgewater.

“He suffers from a personality disorder which makes him likely to engage in sexual offenses if not confined to a secure facility,’’ prosecutors wrote, summarizing a report by a mental health specialist.

Billingslea consented to the move in 2005, firing his lawyer and waiving his right to a trial. Law enforcement officials believe Billingslea may be the only sex offender who has ever voluntarily accepted a commitment.

But less than three months later, he changed his mind, writing the court to say he only agreed to waive his trial because he felt abandoned by his lawyer and distraught that the state’s examiners said he was still sexually dangerous.

“I am not a heartless person,” he wrote the court.

Billingslea continued for several years to seek his release. Despite warnings from the board of state psychologists in 2013, a Suffolk Superior Court jury agreed.

A native of North Carolina, Billingslea grew up in an abusive home where his father beat him with belts and extension cords, court records show. He was also sexually abused as a child.

Billingslea had told psychologists he felt “uncontrollable rage” when he got upset. The prospect of being released was frightening, he said. Just the same, he tried to convince a psychologist that he was ready to leave state custody.

“I’m not going to go home and rape women,” Billingslea told one psychologist. “A lot of people will come here and play a game. They say whatever they think will get them out.”

She determined Billingslea was still sexually dangerous.

While in custody, Billingslea began a romantic relationship with another inmate, according to court records. The two men asked to get married and in 2006 filed a lawsuit when the Department of Correction denied their request.

Officials denied their request largely because they were worried that they would become a target for other inmates. The couple split up by February 2007 and dropped the complaint.

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